Furnace.



UNITED STATES PATENT OFFICE.

ROBERT S. RILEY, F PROVIDENCE, RHODE ISLAND, ASSIGNOR T0 AMERICAN ENGINEERING COMPANY, OF PHILADELPHIA, PENNSYLVANIA, A CORPORA- TION 0F PENNSYLVANIA.

FURNACE.

fication.

This invention relates to furnaces and automatic stokers of the inclined underfeed type, in which fuel is forced through vertical retorts having inclined mouths, in a horizontal direction into the furnace, beneath the incandescent bed of fuel.

The object of the present invention is to secure aA more complete control of the feed of the fuel so that fresh fuel may be fed to the lower part of the fuel bed under all circumstances, and also to increase the capacity of feeding the fuel. l

Another object is to provide an improved construction of wind box and air inlet which will allow air to be carried into the furnace with less resistance than heretofore, will eliminate danger of injury by excessive heat changes'to the walls of the retorts, and will enable repairs of whatever injury may result to be made with very little inconvenience and at an expense which is practically nothing.

Briefiy stated, the invention consists in provisions for admitting fresh fuel directly to the bottom of the retort, so that it may be acted on in the first instance by the lower of a vertically-arranged series of fuel-feeding plungers, wihout requiring first to be pushed a certain distance into the retort by the up- Y per plunger. 1

It also consists in a frame, of which a series placed upon one another forms at the same time part of an air conduit and part of the fuel retort.

0f the accompanying drawings,-Figure l represents a longitudinal sectional view of the forward end of a furnace structure h av.- ing my invention applied thereto, showing also a portion of a steam boiler. Fig. 2 represents a sectional view of part of the furnace Aon line 2-2 of Fig. 1. Fig. 3 represents a' perspective view of one of the frames. c

The same reference characters indicate the same parts in all the figures.

In the drawings, 2 represents one of the walls pf a furnace inclosure, preferably the front wall thereof. Extending through the Specification ot Letters Patent.

Application led March 2, 1909. Serial No. 480,823.

Patented oct. 12, 1915.

wall 2 is a structure consisting of ahorizontal bottom 3 and a plurality of vertical partitions 4 and 5. Alternate pairs of the vertical partitions incluse vertical fuel passages or retorts 6 which open at their rear mto the furnace inclosure and serve to conduct fuel thereinto and to contain the fuel l while the same is being distilled, and the gases being driven off there om and the resldue converted into coke. v

At the front of each retort are plungers 7 and 8 which reciprocate horizontally', one above the other, and servevto force fuel issuing from the hopper 9 into the 'furnace beneath the bed of burning fuel already there- 1n. mechanism which is indicated in the draw-y ings, andthe lower plunger is given a stroke' These plungers are reciprocated by y which may be varied and is preferably less than that of the upper lunger. The actuating mechanisrn for theA plungers is not part of the present invention and a particular description of the same is not necessary to enable the invention -to be` understood. The'main feature of the invention is the provisions by which I am enabled to feed fresh fuel directly to the lower partof the fuel bed in order to govern the thickness and inclination of the same more effectively than has hitherto, been possible.

It will be noted that the lower plunger is almost directly under the upper plunger,

being advanced but slightly beyond the same, and that directly below lthe o ening or passage 10 through which the el is admitted from the hopper 9, there is a passage 11 which extends to the bottom of the retort behind the lower plunger. The two passages 10 and 11 form a continuous chute which allows the fresh fuel to drop from the hopper directly to the bottom of the retort, and to form a column therein extending through the entire height of the chute into the hopper. This column is so located that both plungers may act simultaneously upon it, feeding lthe upper and lower portions thereof separately in approximately parallel horizontal streams into the furnace. There is a partition 12 between the paths of the plungers, the upper part of which extends downward from the bottom of the upper plunger path, and the lower part of which slants upward from the top of the iower plunger path. This partition separates and de nes the fuel-streams propelled by the several pushers, but allows them to spread and merge with one another before belng ejected from the retort and issuing into the furnace inclosure. This pa-rt of the invention is of great .practicalimportance, since it insures a positive feed of fuel directly by the lower plunger un der all circumstances, and by causing fuel to be fed simultaneously by both plun ers, permits a more rapid feed of fuel an an increased capacity of combustion.- It enables'fuel to .be sup lied as fast as itis consumed when the rnace'isl forced to its highest capacity.

l do not limit my invention to the combi.- nation of two plungers only in a furnace of A the character described, but contemplate the use of more than this number, andr declare that my invention includes within its scope any number of plungers arranged in vertical series in each retort,'with provision for allowing the fresh fuel to fall where it can, be

acted on in the irst instance by all the plungers, without requiring to be first disi placed by the upper plunger. rlhe plungers constitute pushing means which propel the fuel from the front of the retorts to and out of the mouths at the rear thereof. Any

pushing means capable of accomplishing this result may be used in placeof the speciic plungers here illustrated, and accordingly l do not limit the scope of the invention to cover only cylindrical plungers. The term plunger is employed for illustration only and not as a term of limitation, and therefore it is to be understood that wherever l use this termin the specification .and claims, l intend to include also any pushing devices whatever capable of propelling the fuel as described,

ln the spaces between the retorts are set the en 'ds of frames 13 which form continuations of the retort walls, and consist of connected side members which form a continuous closed outline, but are open from top to bottom. rlhese frames are placed one upon another at the rear of the partitions 4 and 5, the lowermost frame being placed upon a transversely extending air trunk 14. The side members of the frames thus piled up vconstitute in edect the sides of an air conduit which is located atl the mouth of each retort. Each frame consists of the side members 15 16, the transverse end member the retorts. The converging rear portionv has perforations 20 which provide openings 'nieaeae for the outlet of the air emitted to support combustion. The combustion does not occur until the fuel has reached or passed the openings, and the heat within the retorts is not great at the rear terminations of the partition plates 4 and 5. Consequently,

-removed and a new one substituted, without requiring the furnace to be dismantled, and

at an expense which is so slight as to be negligible.

By reason of the fact thatthe frames themselves constitute the air conduit and have no top plates, with the exception of the uppermost plate 13a, no frictional resistance is odered to the flow of air through the conduit, but a uniform pressuremay be main` tained throughout the entire extent of each of such frame conduits, and the air issues with approximately equal force and velocity through all of the openings 20., Each frame at the rear end has a hook21 which locks into the end of the frame beneath, a notch plane of the retort mouths extends downwardly and rearwardly from the upper lmits to the floors or bottoms of the retorts and crosses the lines in which the plungers feedthe fuel. rl`hus the fuel after emerging from the retorts'forms a continuous sloping bed, the slope of which is suiicient to permit a gravity feed of ash from the upper sur face of the bed to the dumping piates or grates at the rear.

At the rear of the furnace are dumping plates 25 upon which ash and other incombustible products of the fuel collect. These plates are held up by bars 26 which may be withdrawn from time to time to allow the plates to dump anddischarge the matter resting thereon.

An important feature of the invention is the particular construction of the retorts and the manner in which the same are assembled in the furnace. Each retort is an independent box-like casting' having the bottom 3, side walls 4 and 5, as previously described, top arched wallv 30 having the opening 10 to receive the fuel, and the front wall 31 pro'vided with the tubular guides 32 and 33 for the plungers, At the rear end Sti ice

raiz

of the retort is aY vertical web 34 stifened by the side webs or brackets 35. This web lies beside the air trunk 14 which, as before stated, extends transversely of the furnace, and is bolted to the trunk: Thus the latter supports and retainsthe rear ends of the retorts, their forward ends being supportedby a girder 36. The spaces between the reformed with an inclined rear mouth opening into the interior of the furnace, means for admitting air on 'each side of the retort mouth, horizontally reciprocating top and bottom pushers in the front of said retort for feeding fuel therethrough, and an inlet above said pushers, the retort having a passage extending substantially vertically di' rectly from the inlet to the bottom of the retort in rear of said bottom pusher, whereby fuel may be forced into the lower portion of the fuel bed by the lower pusher Without being previously acted on by the upper pusher. A

2. A furnace, a fuel guiding retort formed as a separate entity extending into the furnace and having upright side walls, fuel feeding means in the forward portion\of said retort arranged to travel back and forth in the general direction of the retort, and removable frames placed one upon another so ascollectively to form conduits for air and having emission apertures in their sides,

the air conduits so formed being placed adjacent to the rear terminations of said walls and separated by approximately the width of theretort.

3. The combination of a furnace, a vertical retort having an inclined mouth opening into the furnace at the front thereof, backwardly and forwardly reciprocating pushers mounted at different levels in the forward end of said retort to feed fuel therethrough, and a horizontal partition between said pushers terminating within 'the retort, the said retort having a fuelinlet at its top in rear of said plungers, and a passage extending past said partition beneath said inlet, whereby a stream of fresh fuel may be fed by a lower pusher and merged with that ,fed by an upper pusher before issuing into the furnace.

4. An underfeed furnace including in its -construction a retort having a substantially horizontal bottom and upright sides terminating in a sloping mouth, a fuel pusher" arranged to travel back and forth in a line adjacent to the bottom of said retort, a second fuel pusher arranged to reciprocate back and forth in the upper part of the-rel.' tort, and a fuel inlet opening into the forward end of the fuel passage and in rear of the first-named pusher, whereby green fuel may be fed directly from the inlet to the rear part of the fuel bed without being subjected'to the heat of the fire in the forward part of the furnace.

l 5. A furnace inclosure, a vertical fuel retort passing through a wall of the furnace `and opening within the furnace inclosure, and superposed frames situated at the sides of the retort mouth inside the furnace and forming air conduits for feeding air to the fuel," said frames having lateral openings for emission of the air.

- 6. A furnace including walls, a plurality of vertical partitions extending through awall of the furnace, arranged in pairs, each pair forming a horizontally extending retort, horizontally reciprocating' fuel-feeding plungers in'each retort, frames placed 'one upon another between adjacent retorts and extending beyond the inner termination thereof, inclosing an air duct and forming the mouths of the retorts, and means for-admitting air to the passage inclosed by said frames, each of said frames having lateral air-outlet openings.

7. A furnace, a plurality of vertical partitions extending through a wall of the furnace forming fuelchannels or retorts separated by intermediate spaces, horizontally reciprocating fuel-feeding pushers/in said retorts, and frames superposed upon one another between and at each side of said re- I torts, forming continuations thereof and defining the mouths of the retorts, said frames being open from top to bottom so as collectively to form a continuous air passage, and having perforations in their rear endsy for the outflow of air.

8., A furnace including a front wall, a plurality of fuel passages having vertical side walls and extending in a generally horizontal direction through said front wall into the -furnace inclosure, and frames super'- vposed upon each other between the adjacent side walls of adjacent passages at vthe mouths-of said passages within the furnace,

said frames being open from top to bottom so as collectively to form and inclose an air passage, and having openings foi' emission of air.

9. A furnace, in combination with a retort having vertical sides sloping at their rear ends and a horizontal bottom, a plurality of frames piled one upon another at the rear ends of such sides and in substantial continuation thereof, each frame being open 'from top to bottomy and having emission ori-- fices at its-rear portion; the frames forming collectively an air conduit with a multiplicity of outlets.

a@ p Lisanne 10. An air conduit section consistingl of a frame having a continuous periphery constituted by-two substantially parallel side members, a third member forming an end of the frame perpendicular to said side members, and an outwardly-convexed reaa member forming the opposite end of the frame and having transverse orifices.

11. A furnace, and, in combination therewith a fuel passage having upright sides and ahorizontal bottom, means for propelling. fuel horizontally through said passage into-the furnace, and an air conduit formed Wholly of independentI frames open from t`op to bottom, placed one upon another at the rear and in continuation of the sides of the lfuel passage, and having openings in their sides for the emissions of air. l

l2. A furnace, a fuel passage, a plurality of frames forming the rear continuation of.

said passage, each consisting of parallel side members, a transverse front end member, and a. convex rear end member, all in the same plane, forming a continuous outline and inclosing an open space, said frames being superposed one upon another and forming and inclosing a continuous air passage, havingopenings in certain of their convex end members to permitl outfiow of air.

13. A furnace including in its construction fuel retorts and separated partitions forming the sides of said retorts, and removable frames superposed on one another in rear of said partitions said frames having sides extending in continuation of the partitions and forming continuations of the retorts, and the frames being also open from top to bottom and constituting air conduits for supplying air to the fuel, and having lateral outlets for emission of air.

14. A furnace, an underfeed Stoker hav- -ing fuel retorts, each of said retorts consistingof an independent casting separated by intermediate spaces from the adjacent re-y torts, fuel-*feeding means in the forward ends of said retorts, and removable frames placed one upon another between the rear ends of the retorts, collectively forming air conduits and having apertures in their sides.

15. A furnace, an air trunk having openings in its top side, a plurality of box-like retorts open at their rear ends secured to said air trunk, andseparated by intermediate spaces from one another, each retort having an opening at its top for admission of fuel,

means for feeding fuel into and through the 

